Answer:
Agarose gel electrophoresis is the most suitable method for this analysis.
Step-by-step explanation:
SDS-PAGE, sodium dodecyl sulfate polyacrylamide gel electrophoresis, is a procedure used for visualizing and separating proteins according to their molecular weight. The use of sodium dodecyl sulfate and polyacrylamide gel eliminates most of the influence of the tertiary structure and charge, and proteins are separated solely based on polypeptide chain length. So, if the student suspects that the protein sample is conformed of 4 subunits similar in molecular weight, SDS PAGE will likely not separate them.
On the other hand, an agarose gel electrophoresis can separate proteins based on their size AND charge, so, if you suspect that the proteins are not identical but similar in size, the charge factor can be important to separate them in an experiment.